Foulant layer degradation of dye in Photocatalytic Membrane Reactor (PMR) containing immobilized and suspended NH2-MIL125(Ti) MOF led to water flux recovery

Several researches have been carried out to find a sustainable solution for overcoming the challenge of dyes released by industries in the environment. In this research, a photocatalytic membrane reactor (PMR) based on polysulfone (PSU) with an immobilized and suspended metal-organic framework (MOF: NH2-MIL125(Ti)) was applied for the decomposition of methylene blue (MB) as the model dye of textile wastewater. The MOF and the membranes were characterized through FESEM, XRD, FTIR, Raman, BET, AFM, and contact angle. The MOF incorporation with the concentration up to 0.2 wt% improved the porosity, hydrophilicity and water flux of the membrane, but in higher concentration, the system performance deteriorated due to the agglomeration of the MOF particles. Under UV illumination, MB photodegradation efficiency up to 60% was achieved with immobilized MOF. The combination of immobilized and suspended MOF as a novel strategy in the cross-flow PMR resulted in a significant MB removal efficiency boost up to 97%. Interestingly, using hybrid immobilized and suspended MOF nanoparticles resulted in a flux recovery ratio of 88% due to the self-cleaning properties of MOF nanoparticles and photo-degradation of the foulant layer. Therefore, the novel PMR has a promising potential for developing efficient membrane systems with significant flux recovery to remove dyes and other organic foulants.